Disposable lancet



July 31, 1962 J. C. EHRLICH DISPOSABLE LANCET Filed June 5, 1957ATTORNEYS 3,046,987 DISPOABLE LANCET Joseph C. Ehrlich, 31 W. th St.,New York, N.Y. Filed June 5, 1957, Ser. No. 663,756 3 Claims. (Cl.128-314) This invention relates to a structurally and functionallyimproved lancet as well as a method of manufacturing the same.

This application is a continuation-in-part of my earlier application forpatent Serial No. 410,954 on Lancets, filed February 17, 1954, nowUnited States Patent 2,801,- 633, dated August 6. 1957.

By means of the present teachings a lancet is inexpensively produced.Thereafter, that unit may be conveniently cleaned and sterilized. Itwill preferably come to the doctor or other user suitably packaged sothat it will not be contaminated or subject to contamination. With theopening of the package the lancet is rendered accessible for use. Afterit has once been used, it should be thrown away. Accordingly, there willbe no problem I of cleaning and resterilizing nor will there be anydanger of a subsequent patient or donor becoming infected as aconsequence of a reusing of the lancet without it having been properlycleaned or sterilized after its initial use.

A further object is that of producing a unit of this character which maybe readily employed by the physician or technician and which lancet willnot require as a step to its manufacture the grinding or othersharpening ofany edge zone. With the elimination of this step ofmanufacture it is apparent that costs in the production of the lancetwill be materially reduced.

A further object is that of designing a lancet which may be used withminimum pain to the patient, will assure an adequate blood specimen andwill not distort and may be firmly gripped.

With these and other objects in mind reference is had to the attachedsheet of drawings illustrating practical embodiments of the inventionand in which:

FIG. 1 is a perspective View of a lancet;

FIG. 2 is a face view thereof;

FIG. 3 is a side elevation of such lancet;

FIGS. 4 and Sare transverse sectional views taken along the lines 4-4and 55 and in the direction of the arrows as in FIG. -1;

FIG. 6 is a fragmentary enlarged sectional view of the point end of thelancet;

FIG. 7 shows schematically a strip of material in process of beingpunched or sheared to provide the unit;

FIG. 8 is a view similar to FIG. 7 showing the completion of the formingoperation and taken along the line 8-8 in the direction of the arrows asindicated in- FLG. 6; and

FIG. 9 is a perspective view of an alternative form of lancet.

Referring primarily to FIGS. 1 to 6 the numeral 10 indicates a ribfurnishing a central trough portion preferably extending throughout theentire length of the metal strip from which the lancet is formed. Thistrough is sectionally in the form of an arch which as shown in FIGS. 4and 5 may be substantially semi-circular within the body of theinstrument. To each side of this bent or arched portion marginal zones11 are included Within the strip. While as illustrated and consideringthe strip in its dimension of width, the central portion 10 may onlycomprise approximately one-third of the total. This proportioning of theparts might be varied. In no event, however, should this central portionmaterially exceed one-half of the overall width of the strip.

It is preferred that as shown the base end of the unit be defined by anedge which may extend substantially 3 5,045,987 Patented July 31, 1962perpendicular to its axis. The opposite end of the strip includes anoutwardly tapered tissue-piercing point as at 13. This point portionwill be transversely arched or curved so that its inner face (i.e., theface extending towards the viewer as in FIGS. 1 and 2) will present arecessed configuration. Areas of the marginal zones 11 are indented orcorrugated, as at 12.

Edges 14 extend outwardly from the base of the point 13 and convenientlyin directions perpendicular to the axis of the lancet. These edges areunflanged. In other words, they do not have portions extending outwardlyat right angles to the faces of the marginal zones or parts 11.Preferably, the outer zones of edges 14 are continued in the form ofrecesses 15 which have their corner edges adjacent the point rounded andwhich merge into the side edges of the marginal portions 11.

The zone throughout which the corrugated areas 12 extend shouldordinarily be limited to the central portion of the lancet. Certainly itis preferred that the zone of corrugation-be definitely spaced frompoint 13. In this manner there will be no danger of a stress ordistorting strain being set up in the assembly adjacent the piercingpoint. While the corrugations might take one of several different forms,they will preferably be of a generally triangular configuration as shownin FIG. 2 and will define recesses extending upwardly in each marginalarea 11 beyond the plane in which the uncorrugated parts of these sidesextend. This has been shown in a somewhat exaggerated manner in FIGS. 3,4 and 5.

According to a preferred concept of the invention the material,providing the lancet should be quite thin. For example, .002 to .0025"is found to be satisfactory. With such thickness the material in sheetform has the characteristics of relatively stiff foil. Where somanufactured it is preferred to employ a 302-type stainless steel havinga Brinnell hardness of from 250 to 300. Visualizing the overall lengthof the lancet body to be 1%" and its width to be satisfactoryproportions will involve a width of approximately ,5 for channel portion10 and a length of for point 13. The rounded corners or recesses 15 maybe developed along a radius of .005 The outer corners or entrance edges17 to the recesses 15 may be developed along a radius of, for example,.0l0 to .015. With the width of the channel or groove 10 beingapproximately A the aggregate width of the two side portions 11 will beapproximately The zone of each complete corrugation 12 is, for example,and the depth of each corrugation may be on the order of 4 The depth ofthe channel or groove 10 may be & Conveniently the arching of the pointas a continuation of the rib providing the channel or groove 10continues through a zone 16 which may comprise one-third or one-half thelength of the point. Beyond this zone that point is preferably flat,although of course it may be arched through to its outer end.

It is found, if the parts are dimensioned at least generally to haverelative proportions and lengths as aforestated, that a lancet unit isfurinshed which is eminently desirable and will properly perform itsfunctions even if the material of the sheet have a thickness of only.0025. In this connection it will be understood that the rib or grooveportion 10 serves as a reinforcement extending axially of the unit andwhich is braced by the adjacent side portions 11. The corrugations orserrations 12 being preferably limited to the central zone of the unit auser will instinctively grip that zone between his thumb and forefinger.So gripped the point will be in properly spaced relationship to thegripping zone. Also, any distortion of the metal incident to forming theserrations or corrugations will be at a point relatively remote from thepiercing element of the lancet. By having the width of the channel notin excessof one-half of the overall width of the strip thestability ofthe instrument will be assured, free from objectionable distortingtendencies.

Additionally, the extreme outer zone of the point being preferably flat,a pure puncturing or cutting action occurs as the point pierces theepidermis and its side edges cut through areas beyond the initial pointof piercing. This action will continue until the arched or curved zone16 of the point passes through the skin. Due to the configuration ofthis portion, the wound which has been created by theextreme outer endand the side edges of the cutting point will be gaped. In other words,the severed tissue will be spread apart thus inducing a flow of blood.The gripping of the writ in line with the serrations and the consequentforce exerted may cause a slight bending of the side strips or zones 11.Whether these zones have extended in a straight line as shown especiallyin FIGS. 4 and 5, or have terminated short of or beyond such a straightline, any such flexing will cause the channel portion It) to tend toarch to a more acute degree. If this result is evident even in the zone16 of the point, the acuteness of the arch will merely result in agreater gaping of the wound. This obviously will have a desirable endresult. 7

With the outer end of the point 13 preferably substantially flat, aminimum of pain will be experienced by the patient as that pointpenetrates the skin. Edges 14in contact with the surface of the skinwill serve as stops arresting further penetration of the point. Byhaving the channel and the base of the point not in excess of one-halfof the overall width of the unit, it is unnecessary to incorporate stopflanges in edges 14 despite their preferably very small thickness.Incident to the rounded edge portions 17 it is apparent that even withthe lancet body manufactured of very thin material, no secondary cuttingedges or points will exist.

While it is apparent that many of the teachings of the presentapplication will be of value in a lancet which may be formed of amaterial having a thickness substantially greater than the range aforeindicated, it is preferred that the sheet material from which the lancetbody be formed shall be around .0025" in thickness. It has been foundthat using such a gauge of material it is feasible to produce the lancetwith adequately sharp cutting edges without having to resort to anygrinding or honing operations for those edges. More particularly and asshown in FIGS. 7 and 8, the tool elements involved in a punching orshearing operation have been indicated by the numerals 1S. and 19. Thesheet to be operated on by these tools has been indicated at 21' in FIG.7. As the tools cooperate in the manner shown in FIG. 8, the point zone13 of the instrument is produced by removing excess material to eitherside of this penetrating element. In such removal edges will be leftwhich will be entirely free of burrs, fins or other undesirableprojecting or adhering portions. In other words and as shown in FIG. 8the edges will extend substantially perpendicular with respect to thefaces of the point and these edges will be clean. The thickness of thematerial used being of the nature indicated, it is found that theseedges serve adequately to cut the tissue in a lateral direction and alsoat tangents to that direction as the point has its zone '16 embedded inthe epidermis. Therefore, a minimum of pain is experienced by thepatient.

As a consequence of the preferred contour of the point a substantiallyhalf-round incision results. That incision tends to gape. Accordingly,this avoids premature closing of the wound and clotting is also delayed.It is obvious that despite the fact the point is relatively short andeasier and immediate yield of blood flow in adequately supply results.With an incision of this type a milking of the finger tip is unnecessaryand therefore a true specimen of the patients blood is obtained with aminimal dilution of that blood by tissue fluid. The angle and length ofthe piercing point insure that the incision is corpuscles traumatized.The edges 14 automatically 7 control depth of penetration by the pointand due to the rounded corners 15 and 17 these edges may contact theepidermis without there being any danger of a secondary and undesiredincision occurring.

As in FIG. 9 it will be understood that various forms of unit might beproduced involving structures difierent from those shown in FIGS. 1 to 6inclusive. Thus, in FIG. 9, 21 indicates the body of a strip formed ofthin metal. This is corrugated as at 22 so that its body will bereinforced against collapse. The forward end of this body terminates ina piercing point 23. This is curved or angularly bent in a manner, forexample, identical with zone 15 of the previously described point. Thecurvature or bending is continued as at 24 into the body of the lancetto a zone adjacent that occupied by corrugations 22. Itis thus apparentthat the forward portion of the lancet is reinforced but that the curvedor channel portion 24 need not necessarily extend throughout theentireof said body portion; said piercing projection having a baseportion integral with said body portion and tapering to a piercing pointat its outer end; the body portion of said strip adjacent saidprojection being wider than the base portion of said projection therebypresenting shoulders adjacent said projection at each side thereof tolimit the extent to which the piercing projection may penetrate tissue;the strip of material being composed of 7 thin normally flexible sheetmetal and formed with a longitudinal stiffening rib extending from thebase portion of said projection into the body portion; and the pointedouter end of the projection beingrelatiyely flat to facilitatepenetration into the tissue with the projection at its base portion inthe area of said rib being substantially arcuate to provide a gapetissue incision.

2. A lancet for piercing 7 tissue and letting blood samples therefromcomprising: an elongated strip of material including a finger grippingbody portion and an integral tissue piercing projection extendingaxially from one end of said body portion; said piercing projectionhaving a base portion integral with said body portion and tapering to apiercing point at its outer end; the body portion of said strip beingwider throughout its length than the base portion of said projectionthereby presenting shoulders adjacent said projection at each sidethereof to limit the extent to which the piercing projection maypenetrate tissue; the strip of material composed of thin normallyflexible sheet metal and formed with a longitudinal arcuate stifieningrib extending from the base portion of said projection into the bodyportion; and the pointed outer end of the projection being relativelyfiat to facilitate penetration into the tissue with the projection3,046,987 5 ing a shoulder provided by the width of said strip adjacentsaid projection to limit the extent to which the piercing projection maypenetrate tissue; the strip of ma- 6 References Cited in the file ofthis patent UNITED STATES PATENTS terial 'being composed of thinnormally flexible sheet metal 528,569 Star? 6, and formed with alongitudinal stifiening rib extending $864,812 Till-111161 P from thebase portion of said projection into the body 988,620 Bofiy P portion;and the pointed outer end of the projection being 1,573,681 Dafreaux 16,relatively flat to facilitate penetration into the tissue with 2,706,482Grlfljtltts P 19, the projection at its base portion in the area of saidrib 2,801,633 Ehrlich 6, being substantially arcuate to provide a gapetissue 10 2,908,268 Guest 13, incision 2,913,204 Stewart NOV. 17,

